This project was initiated to study the role of catecholamines in the central and peripheral nervous system in experimental and genetic hypertension and stress. Changes in brain adrenaline and noradrenaline occur in all forms of hypertension studied (DOCA-salt, neurogenic, spontaneous and sodium dependent). Increased synthesis of adrenomedullary catecholamines is present in all types of hypertension. Acute and chronic stress also result in similar changes in brain adrenaline metabolism. Sodium dependent hypertensive rats (Dahl rats) show specific changes in brain catecholamines. Some of these changes are related to the hypertension and some to the ingestion of a high sodium diet. Genetic spontaneously hypertensive rats present changes in vasopressin and somatostatin levels in brain under normal conditions and after acute stress. Rats with diabetes insipidus (Brattleboro rats) show localized and specific changes in brain catecholamine metabolism.